Masters, AdamManners, Harry ArthurHarry ArthurManners2021-10-222021-10-222021-05almahttp://hdl.handle.net/10044/1/92199The study of dynamics in planetary magnetospheres is critical to a fuller understanding of the flow of mass and energy through these systems. Prominent among these dynamical features are waves occupying the ultra-low frequency (ULF) band, which represent reconfigurations forced by global-scale perturbations. These waves have been shown to establish resonances of the entire magnetosphere, exciting the normal modes of the system. Enigmatic pulsations with periods spanning 5 – 60 min have been observed in the magnetosphere at Jupiter for over forty years in various datasets, yet their relation to ULF waves and magnetospheric resonance have remained a mystery. This thesis investigates the broad range of quasi periodic ULF features at Jupiter. First, we establish that the bulk of these observations are consistent with ULF magnetohydrodynamic (MHD) waves. We use a model to demonstrate that the toroidal (east-west polarized) resonant mode is consistent with all the observations. We then present a heritage survey of all the magnetometer data available and search for large amplitude ULF waves. We show that the waves occur most often close to the magnetopause at noon and along the dusk flanks, but waves with the greatest power occur close to the plasma torus at Io’s orbit. Finally, we probe the powerful waves in the torus in greater detail. By modelling the region, we show the torus likely has independent resonance modes, with a markedly different structure than elsewhere. The work presented in this thesis establishes that ULF waves abound in the magnetosphere at Jupiter and play at least as great a role in dynamics as at Earth. Understanding the complex behaviour of the system, as revealed by the ongoing Juno mission and to be followed up by the forthcoming JUICE mission, will require yet greater investigations into ULF phenomena.Creative Commons Attribution NonCommercial LicenceThesis or dissertationhttps://doi.org/10.25560/92199